Subject: Re: [PATCH] submodule: configure submodule.<name>.path on add and init

From: Jens Lehmann <[email-masked]>
Date: Tue, 25 Sep 2012 22:58:43 +0200

Am 24.09.2012 22:43, schrieb Junio C Hamano:
> Jens Lehmann <[email-masked]> writes:
> 
>> Am 24.09.2012 21:30, schrieb Orgad Shaneh:
>>> In order to read diff options for a submodule, its path must be configured
>>> ---
>>>  git-submodule.sh |    2 ++
>>>  1 file changed, 2 insertions(+)
>>>
>>> diff --git a/git-submodule.sh b/git-submodule.sh
>>> index 3e2045e..f97bb62 100755
>>> --- a/git-submodule.sh
>>> +++ b/git-submodule.sh
>>> @@ -359,6 +359,7 @@ Use -f if you really want to add it." >&2
>>>  			esac
>>>  		) || die "$(eval_gettext "Unable to checkout submodule '\$sm_path'")"
>>>  	fi
>>> +	git config submodule."$sm_path".path "$sm_path"
>>>  	git config submodule."$sm_path".url "$realrepo"
>>>  
>>>  	git add $force "$sm_path" ||
>>> @@ -476,6 +477,7 @@ cmd_init()
>>>  				url=$(resolve_relative_url "$url") || exit
>>>  				;;
>>>  			esac
>>> +			git config submodule."$name".path "$name" ||
>>>  			git config submodule."$name".url "$url" ||
>>>  			die "$(eval_gettext "Failed to register url for submodule path '\$sm_path'")"
>>
>> Nack. The path must only be configured in .gitmodules or we'll
>> never be able to rename the submodule directory.
> 
> That sounds sensible on the surface, and the rejection of this is
> probably the right thing to do, but then how would the name/path
> mapping work without .gitmodules?  Historically, you did not have to
> have a .gitmodules in-tree at all in order to use submodules
> locally, but if discovery of submodule.$name.ignore depends on
> having the in-tree .gitmodules file, that sounds like a minor
> regression to me.

AFAIK the name/path mapping was added to enable moving submodules
around in the work tree without having to adapt its $GITDIR/config
entries every time you checkout a commit where the submodule's work
tree is moved someplace else inside the superproject's work tree.
Nowadays we also use that to consistently store the submodule's
.git directory under "modules/<name>" inside the superproject's
.git directory no matter what its current path is.

You still don't need a .gitmodules file to use submodules locally,
but then moving around these submodules is not - and has never
been - that easy. To use the ignore setting without a .gitmodules
file you'll just have to set both submodule.$name.ignore and
submodule.$name.path (to provide the mapping, in most cases path
and name will simply be the same) in your $GITDIR/config and
everything will work just fine.